ELECTRON MICROSCOPIC STUDIES ON THE SUPERIOR CERVICAL GANGLION OF GUINEA PIGS IN THE NORMAL AND EXPERIMENTAL REILLY'S PHAENOMENON

Abstract

The experimental studies to be presented in this paper were performed with a purpose of ob-taining some informations about the relationship between Reilly's phenomena and morphological changes of the peripheral autonomic nerve cells under the observation with the electron-microscope. First. of all, the detail of the structure of the superior cervical ganglion cells of the guinea pig was studied and then changes in the structure of these cells were studied in two groups of animals. The first group contisted of those animals to which a minute amount of croton oil was injected be-neath the mucous membrane of the lips and palate to bring the animal into a condition of shock. The animals of the second group were injected repeatedly with diluted croton oil and kept alive for twenty days.In the superior cevical ganglion cells of the normal guinea pig, the endoplasmic reticulum which are visualized in the masses representing the Nissl's bodies are almost flat and arranged in a regular parallel fashion. Mitochondria, Golgi apparatus, neurofilaments, axonfibrils and infoldings of the cell membrane can also be visualized. Each nerve cell is surrounded by several capsular cells and each capsular cell is clearly delineated. Nucleoli were observed to consist not only of granular masses connecting nucleolonema but also of groups of fine granules which are present more abundantly around the area next to the nuclear membrane. Some interesting informations were also obtained of the structure of nucleoli and of nuclear membrane.It is well documented in the observations with the conventional microscope that various stressful conditions induce chromatolysis. With the aid of the electron microscope, it was observed that in the animals of the second group, the chromatolysis is manifested as spreading, decrease in number or disappearance of the endoplasmic reticulum, and is accompanied by convoluting of nuclei as well as various morphological changes of the nucleoli, whereas in the animals of the first group, no diffe-rence from the nomal morphology was observed. On the other hand, the histological picture of the tissue of the liver and kidney was the same in these two groups.This result seems to indicate the participation of the superior cervical ganglion in the mecha-nism of maintaining homeostasis within the organism. The paucity of morphological changes in the ganglion cells of animals of the first group seems to indicate the condition before any morphological changes visible with the electron microscope could have taken place, and that under the conditions to which these animals were exposed, the stress affected the entire body so violently and rapidly that the ganglion cells had no time to show their reactions in their full extent before its fatal effect became manifested.